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Delisting of the Peregrine Falcon

On August 20, 1999 the peregrine falcon was removed from the federal list of Threatened and Endangered Species. The recovery effort began in 1970 and included release of over 6,000 captive-bred falcons in 34 states; over 600 of these birds were released in Montana. In the mid-1980’s there were no known breeding pairs of peregrine falcons in Montana. By 1994 recovery efforts had resulted in 13 known breeding pairs. Currently, there are over 90 known breeding pairs in the state.

Peregrine falcons were historically found throughout North America in mountain ranges, coastlines and river valleys. Like the bald eagle, peregrine falcon populations plummeted in the 1940 – 1960’s because of the widespread use of DDT and other pesticides. In a process called bioaccumulation, relatively low levels of pesticides in the prey of peregrines, often songbirds and shorebirds, magnified in the fatty tissues of peregrines. These higher levels of DDE, a metabolite of DDT, compromised the peregrine falcon’s ability to manufacture calcium for egg development, leading to reproductive failure during incubation.

With the banning of DDT in 1972, falconers and biologists joined forces to initiate one of the most successful captive-rearing programs. Juvenile peregrines were released in to the wild through a process called hacking that allows young birds to acclimatize to their environment gradually without becoming accustomed to humans. Young birds for release in the U.S. were reared in facilities operated by The Peregrine Fund, Santa Cruz Predatory Bird Research Group, and the Midwestern Peregrine Recovery Group.

Clearly a conservation success story, the peregrine falcon once again graces the mountains of Montana. Through the leadership of the Montana Peregrine Institute, the Montana Peregrine Falcon Working Group continues to monitor nesting peregrine falcons in Montana. Our state monitoring program is conducted in cooperation with the federal post-delisting monitoring strategy for peregrines that calls for surveys every 3 years between 2003 and 2015.